Refrigerating apparatus



Jan. 9, 1962 'J. M. MURPHY ETAL 3,016,183

REFRIGERATING APPARATUS 4 Sheets-$heet 1 Filed April 19. 195'? INVENTORSJohn M. Murphy Marion K. T cker Thoma; H. Fog) The/r Atforne Jan. 9,1962 J. M. MURPHY ETAL 3,0l6 l83 REFRIGERATING APPARATUS Filed April 19,1957 v 4 Sheets-Sheet 2 INVENTORS Ja/m M. Murphy Marion K. Tucker ThomasH. Fog! The/r Afro/n 1952 J. M. MURPHY ETA'L 3,016,183-

REFRIGERATING APPARATUS 4 Sheets-$heet 3 Filed April 19. 195'? Fig. 4

Fig. 6

68 70 Fig. 7

INVENTORS Join] M. Murphy BY Mar/on K Tucker Thomas Fog! The/r AhomeJan. 9, 1962 J. M. MURPHY ETAI. 3,015,133

REFRIGERA'I'ING' APPARATUS Filed April 19. 19s? 4 Sheets-Sheet 4 32 3INVENTORS 5O Joli/ 1 M. Murphy BY Mar/on K Tue/re! F19. Tho/nag H'ogfTheir Attorney 3,016,183 Patented Jan. 9, 1962 3,016,183 REFRIGERATINGAPPARATUS John M. Murphy, Marion K. Tucker,'and Thomas H.

Fogt, Dayton, Ohio, assignors to General Motors Cor-' poration, Detroit,Mich., a corporation of Delawar Filed Apr. 19, 1957, Ser. No. 654,030

2 Claims. (Cl. 230-139) This invention relates to refrigeratingapparatus and more particularly to asealed motor compressor unit.

It is an object of this invention 'to provide a motor compressor unitwhich lends itself to mass production methods.

Another object of this invention isto provide a motor compressor designwherein a change either in. the motor or a change in the size of .acompressor cylinder serves to;v 15

change the output of' the compressor. without' the need for materiallychanging any'of the components.

Still another object of this invention is, to provide an improvedarrangement for mounting mechanism within a casing. p

Further objects and advantages of the present invention will'be apparentfrom the following description, reference being bad to the accompanyingdrawings wherein a pre ferred form of the present invention is clearlyshown.

In the drawings:

a motor compressor ferred embodiment of the invention and includes asche-' matic showing of the refrigerant circuit; 2

FIGURE 2. is a fragmentary sectional view taken substantially on line 22of FIGURE 1;

stantially on line 3-3 ofFIGURE 1;

FIGURE 4 is a fragmentary sectional view on an en larged scale takensubstantially on line .4-4 of FIG-' URE 3;, v I

FIGURE 5 is a fragmentary sectional view on an en-' larged scale takensubstantially online 5-5 of FIG- URE3; I I

.FIGURE 6 is a fragmentary sectional view on an enlarged scale takensubstantially on line 66 of FIG- URE 2;

FIGURE 7 is a fragmentary sectional view on men larged scale takensubstantially on lin'e'7--7 of FIG- FIGURE 8 is a view partly in sectionshowing a portion of the mounting ring which is used in supporting themotor compressor mechanism;

FIGURE 9 is a fragmentary sectional view taken substantially on line 9 9of FIGURE 10 showing the arrangement of the discharge niuffler chambersand the discharge check valve; 7 i

FIGURE 10 is a sectional view taken on line 10-10 of FIGURE 11 andshowing in dot dash lines the relative location of portions of thecompressor mechanism; and

FIGURE 11 is a sectional'view taken substantially on line 11-11 ofFIGURE 10. v

Referring now to the 'drawings'wherein a preferred embodiment of theinvention has been shown, reference numeral 10 designates an 7 invertedcup-shaped casing element which serves to enclose the motor compressormechanism which has secured thereto at its open end a plate 12. Theplate 12 is. preferably welded to the casing portion 10 at 14. The motorcompressor mechanism comprises a main casting 16 which is resilientlysupported within the casing 10 by means of coil springs 18 which rest onsupporting brackets 20.

In the compressor shown, three of these mounting brackets 20 areprovided whereas the actual number may be varied without departing fromthe spirit of the invention. The mounting brackets 20 are welded to asplit ring like element 22 which has its lower edge resting on thebottom plate 12 as best shown in FIGURE 1. A single cleat 21, which hasits upper end spot welded to the casing portion 10,1oosely overlies thereduced ends of the split ring 22, as shown in FIGURE 1, so as toposition the ring and limit its upward movement.

The casting .16 is provided witha' central bearing boss 24 in which themain drive shaft 26 is jou'rnalled. A

- motor rotor 28 is secured to the upper end of the shaft 26 and thelower end of the shaft 26 is provided with an eccentric portion 28 whichserves to drive an impeller 30 which operates within the compressionchamber 32 formed in the cylinder plate 34. The plate 34 is held inplace between the bottom of the casting 16 and a lower end plate 36 bymeans of cap screws 38. A motor stator rests on the top surface of thecasting 16 and is held in place by means of several cap screws 39. Thetop surface of the casting 16 is made perfectly flat so that it ispossible-to shift the motor stator sidewise on the casting 16 so as toadjust the alignment of thestator withthe motor rotor. The casing 10 isprovided with an inturned boss 41 which limits the upward movement ofthe motor shaft 26. The lowerjend of the shaft 26 is provided with areduced bearing portion 40 which is journalled in the end 5 FIGURE 1 isa vertical sectional view showing a pre-' 2 plate '36. )Suitable oilfeed grooves 42 are provided on the shaft for feeding oil to the bearingsurfaces.

The cylinder plate 34 as best shown in FIGURE 3 of the drawing, servesto slidably support a divider block 46 which is urged. into slidingengagement with the im- I 30 FIGURE 3 is a fragmentary sectional viewtaken sub peller 30 by means of a coil spring 48. The gas to becompressed is supplied to the compressor through the suction line 50which is in the form of a copper or aluminum tube having its endprojecting into a passage 52 provided in the lower end plate 36 as bestshown in FIGURES 6 and 11. A steel sleeve 54 is driven into the end ofthe tube 50 so as to securely hold the tube in place without any leaksbetween the, walls of passage 52 and the outer walls of thetube 50. Byvirtue of this construction, the need for silver soldering or brazingthetube in place has been eliminated and this has the added advantagethat it is possible to disconnect the tube from the compressor withoutdamaging the compresson v .The gas to be compressed flows from the tube50 into a valve chamber 56 in which a check valve. 58 is located. Afterflowing past the check valve 58, the gas enters a chamber 60 formed inthe lower portion of the main casting 16. The chamber 60 not only servesto muflle the noise usually produced by the suction gas but also servesas an unloading chamber. Thus, after the compressor has been standingidle for a period of time, a certain amount of gas will tend to leakpast the compressor parts i prevents any appreciable flow of gas fromthe chamber 60 into the low pressure side of the system. When the Icompressorifirst starts operating after a period of shut down,'the gasin the unloadingchamber will be at substantially the same pressure asthe gas at the outlet of the compressor With the result that during thefirst'few revolutions of the compressor, ,the compressor will not berequired to operate with a high pressure differential.

Consequently it is possible to use a motorwith a lower starting torquetha n would otherwise be possible. .The" gas leaving the unloadingchamber 60 passes through a wire screen or filter; element 62 beforeentering the, compression chamber 32. The unloading chamber is formedduring the casting of the frame 16 and consequentlyit does not addmaterially to the cost of the compressor.

The compressed gas leaves the compression chamber 32 through a dischargeport 64 (see FIGURES 2, 7 and 9). A check valve 66 is provided adjacentthe discharge port 64, as best shown in FIGURE 9. This valve includes acoil spring 68 which is held in place by means of a stamping 70 wherebyspring pressure is applied continuously to the valve 66 for'biasing ittowards the closed position. The check valve plate 66 is provided with apin 72. which registers with a hole 74 in the plate 36 so as to preventrotation and needless wear on the plate 66. The gas which flows past thedischarge plate 66 is directed into an aperture 76 which leads to aseries of muffle-r chambers 78 which are formed by drilling alignedholes in the cylinder plate 34 and the lower surface of the casting 16as best shown in FIGURE 9. Communication between the muffler chamber 78is provided by cutting slots 80 in the walls which separate the mufilerchambers from one another. The compressed gas leaves the muffier chamber78 through the line 80 which is also held in place within an apertureformed in the lower end plate 36 by means of a steel sleeve 84 which ispressed into the flared end of the tube 82.

The line 82 leads to a super heat removing coil 83 which is mountedexteriorly of the compressor in accordance with standard practice. Theoutlet of the super heat removing coil discharges the compressedrefrigerant back into the casing so as to deposit entrained oil in thecasing 10 before the compressed refrigerant is discharged into thecondenser 85. The condensed refrigerantfiows from the condenser throughan expansion valve 87 and into the evaporator 89 before returning 'tothe suction line 50. A conventional processing valve 91 for use inevacuating and charging the system with refrigerant is provided asshown.

A pressure operated valve 100 is arranged in the lower end plate 36 andis of the type which is designed to open when the pressure in the maincompressor casing exceeds a safe value such as 600 to 800 pounds persquare inch. Opening of the valve 100 serves to feed the high pressuregas directly into the compression chamber 32via the port 102 so as tooverload the compressor and thereby cause the usual thermal overloadswitch 103 to stop further operation of the compress-or. Without thisfeature there are certain circumstances under which dangerously highrefrigerant pressures may build up in the compressor housing 10. Thus ifa very minute leak should develop in the evaporator so as to allow airand moisture to enter the suction line at a very small rate, theincoming moisture would eventually cause freeze-up of the restrictor orexpansion valve leading to the evaporator so that the high side pressurewould very gradually build up by very small increments until thepressure in the compressor casing 10 and coils 83 and 85 would becomehigh enough to damage the refrigeration parts. Due to the very smallamount of moisture in the air entering the compressor through the leak,the compressor never becomes overloaded unless the valve 100 opens so asto completely fill the compression chamber with the high pressure gasand thereby cause stalling of the motor so as to cause the conventionalthermal overload protector switch to stop the motor.

The exterior of the compressor housing 10 is provided with sheet metalfin means which are formed by punching out tongue-like fin projections104 from a strip of sheet metal and then foreshortening the edges of thestrip by forming plaits in the edges of the strip between the adjacentfin elements so as to bring the fin elements closer together.

While the form of embodiment of the invention as herein disclosedconstitutes a preferred form, it is to be understood that other formsmight be adopted, as may come within the scope of the claims whichfollow.

What is claimed is as follows: I

1. In a refrigerant compressor, the combination, an inverted cup-shapedstamping forming an outer casing element, a closure means for the openend of said inverted cup-shaped stamping, a split mounting ring restingon said closure means, a cleat carried by said cup-shaped stamping forengaging the ends of said split Plllg for holding the same in placeagainst said closure means, cornprcssor mounting brackets having theirlower ends secured to said split ring and having spring seats at theirupper ends, spring means resting on said seats, a motor com= pressorsupporting frame resting on said spring means so as to be resilientlysupported within said casing, a cylinder plate secured to the bottom ofsaid frame and having a circular compression chamber formed therein andclosed on the one side by saidframe, an end plate secured to saidcylinder plate for closing the other side of said compression chamber,piston means operating within said compression chamber, and motor meanscarried by said frame for operating said piston means.

2. In a refrigerant compressor, the combination, an inverted cup-shapedstamping forming an outer casing element, a closure means for the openend of said inverted cup-shaped stamping, a split mounting ring restingon said closure means, a dent carried by said cup-shaped stamping forengaging the ends of said split ring for holding the same in placeagainst said closure means, compressor mounting brackets having theirlower ends secured to said split ring and having spring seats at theirupper ends, spring means resting on said seats, a motor compressorsupporting frame resting on said spring means so as to be resilientlysupported within said casing, a cylinder plate secured to the bottom ofsaid frame and having a circular compression chamber formed therein andclosed on the one side by said frame, an end plate secured to saidcylinder plate for closing the other side of said compression chamber,piston means operating within said compression chamber, motor meanscarried by said frame for operating said piston means, means fordirecting the compressed refrigerant leaving said compression chamberinto thermal exchange relationship with said casing element, and astamped sheet metal fin strip secured to the exterior of said casingelement, said strip having integrally formed tongue like fins projectingfrom its central portion and having plaits formed in its edge portions.

References Cited in the file of this patent UNITED STATES PATENTS1,683,842 Mullen et al. Sept. '11, 1928 1,915,097 King June 20, 19331,965,419 Lipman July 3, 1934 2,045,014 Kenney et al. June 23, 19362,094,323 Kenney et a1. Sept. 28, 1937 2,175,071 Walker Oct. 3, 19392,395,065 Rataiczak Feb. 19, 1946 2,440,593 Miller Apr. 27, 19482,493,171 Touborg Jan. 3, 1950 2,545,600 Berry Mar. 20, 1951 2,597,243Hubacker May 20, 1952 2,713,969 La Flame et al. July '26, 1955 2,735,698Brinen Feb. 21, '1956 FOREIGN PATENTS 877,709 France Sept. 14, 1942

